三位数连加连减

列竖式计算：（红色字体要验算）

844+932-226=    199+398+456=    801+160-278=    814+551-450= 

    175+505-320=     481+21-420=    665+1000-133=    729+180-233=  

306+812-562=    128+611-578=    263+206+352=     4+104+323= 

脱式计算：   

750-253+368   659-567-274     577-545+368    599-481+368

 =             =              =               =

=             =              =               =

1-353+123    940-456+368    979-488+143     680-502+368 

=              =              =               =

=              =              =               =

637-631+143     911-75-274     975-883+143    4-162+368

=               =              =               =              

=               =              =               =